Process of desulfurizing ores and metals.



, UNITED STATES PATENT OFFICE.

-ALIBEBT E. enEnN or CHICAGO, ILLINOIS, ASSIGNOR r AMERICAN ELECTRIC 'SMELTING AND ENGINEERING COMPANY, or sr. LOUIS, mssoum, A conrons- 'r oN or MISSOURI.

PROCESS OF DESULFUBIZING ORES AND METALS.'

1,056,900. No Drawing.

To all whom it may concern Be it known that I, ALBERT E. GREENE, a citizen of the United States, residing at I Chicago, inthe county of Cook and State of Illinois, have invented a certain new and, useful Improvement 'in Processes of Desulfurizing Ores and Metals, of which the following isa full, clear, concise, and exact description.

My invention relates to an improved process of desulfurizing pig iron and iron pyrites.

The chief object of'my invention is to refine pig iron .or iron pyrites byextracting therefrom sulfur or like impurities and at the sametime to avoid the production of noxious fumes A further objectis vto convert the eliminated impurities into'valuable by-products.

Myinv'ention consists in adding to the above mentioned ore or metal a slagging agent (such as one or more of the compounds of the alkaline-earth group, as, for example, lime or fluorspar) and a reducing agent, as, forexample, coke, and heat-in thecharge to a temperature suificiently high to cause the sulfur or like impurities to combine with the metallic element of the slag forexample in the case of a lime slag, to 0rm calcium sulfid. I

The process is preferably carried out in an electric furnace, since temperature regulation-is more readily secured in such furnace.

The sulfid corn-pounds after being slagged from the metal in the u'sual'manner can sub-' seque'ntly oxidized into -sulfates ,.thereb becoming converted into "vs'zluablevby-pro As illustrative of theproeessIwill first describe the treatmentof pig iron for the removal of sulfur therefrom. The'charge consisting of pigiron or spiegel iron, a sultable slag, as,

or eX1mple,l 1me' and fluorspar, and a reducin agent such as'coke is ntroduced into a sultable electric :vfurnace. -Under the influence of a temperature ofl-aboui' 1300? to 1400 C.,"the reducing agent acts on the lime and fluorspar in such a manner-as to in theform' of sulfidsl There is, of course, no decarburizing of the metal onaceount of the presence. of carbon in the slag. It is Patented-Mar, 25, 1913.

cause it to take up the sulfur from the metal essential that oxids o'f'iron and manganese I should be practically absent,- for otherwise. the sulfur will not'bejtaken up by the slag.

The sulfid after separation of the slag from the metal maybe oxidized at approximately a temperature of 400] C; to sulfate by means of steam under pressure. The slag is thus converted into a valuableby-product.

In the case of the process of my invention the absence of any oxid of the metal-or metals being refined permits the calcium or other alkaline earth metal to What I claimis:

freely combine with sulfur to form ,sulfids.-

containing sulfur to. eliminate-the sulfur therefrom, which consists in melting ,a charge of said iron compound together with a reducing'agent and a slagf composedof an alkaline earth compound such as lime or fluorspar, in an electric furnace, at a temperaturehigh enough tocause th'e sulfur to combine with the metallic element of theslag without appreciable formation of noxious fumes. v -v 2. The process of removing sulfurfrom pig iron, whichc'onsists inj'heating molten pig iron in an electric furnace simultaneously with a lime slag and-areducing'agent to a temperature high lenoiig'h to se arate' the sulfur andphoshorusj as sulfi s and 4 phosphids, respectiv' y- 3; The pi'oce'ssof treating pig iron, whichconsists in maintainingitjat a temperature of approximately 1350; G; an "electric I furnace, and simultaneously treating It with a suitable slag and a reduclng' agenttto eparate the sulfur 5 Y i i I In witness whereof, I, hereunto'subscribe my name this 4th day of August ALID QI QI ON ALBERT E. '2

" Witnesses:

= Gno. C.-DAvIsoN,

GEORGE E. Foam. 

